Search Results

Search found 9765 results on 391 pages for 'skill building'.

facebook twitter digg google delicious technorati stumbleupon myspace wordpress linkedin gmail igoogle windows live tumblr viadeo yahoo buzz yahoo mail yahoo bookmarks favorites email print

Page 10/391 | < Previous Page | 6 7 8 9 10 11 12 13 14 15 16 17  | Next Page >

  • Interested in Free Website Building?

    Using free website building is a great and cost effective tool. Not only do you have tutorials to help you, but you receive free hosting as well. Everything that is given to do to build your website is understandable.

    Read the article

  • Purpose of building file using Make

    - by foo
    I am trying to understand what is the purpose of making files using commands such as cmake .. and make, I have tried looking online but there is no concise explanation on its purpose that i could find. Also, is it necessary to use make on a project folder that is not built in order to use the source (C++) in other projects. I know this may be a simplistic question, but as i am fairly new to building files, any information or references would be much appreciated.

    Read the article

  • Forum Link Building For SEO

    There is no denying the fact that content and traffic are the two most important aspects that will determine the success of your website on the Internet. One of the techniques that you will find any professional SEO company employing is that of forum Link building.

    Read the article

  • SEO is Not All About Link Building, It's About Execution

    The most people hear the term "SEO", it is generally heavily associated with link building, and dominating in the search engines. Truth be told, whilst this still remains a large part of what it is that you do to rank, it is not the be all and end all. In fact, the most important aspect of SEO is in how you execute it, and this is why the success rate of those who learn methods is actually quite low. Let me demonstrate.

    Read the article

  • The Importance of Link Building For SEO

    Link building is the process through which one can make his site popular on the search engines. The process is also called search engine optimization (SEO). A link is a URL on your site that points to some other website. A site ranks high on a search engine if it is able to generate a lot of traffic towards itself. It is one strategy which helps a lot to improve the rank of your website.

    Read the article

  • Interested in Free Website Building?

    Using free website building is a great and cost effective tool. Not only do you have tutorials to help you, but you receive free hosting as well. Everything that is given to do to build your website is understandable.

    Read the article

  • Building Your Own Website

    Here we discuss what you do and don't need when building your own website. We also give you recommendations on what to use to save a lot of money, time, and frustration.

    Read the article

  • Finding the Best Website Building Software

    Do you want to be a successful businessman online? If you say 'Yes' then you must ready with the all the tasking research that you will subject yourself in order to find the best website building software. Surely you must ask yourself what kind of software was used on the most frequented sites on the web, and if you use it, would you get the same response?

    Read the article

  • Effective Link Building Techniques - Part 1

    There are four main areas when optimising your site. The first three: site structure, keywords and on page optimisation are all under your control but the fourth - link building is a little different. In this article we will take a look at what you can do to generate more quality links to your site and also take a look at many of the 'schemes' out there looking to deprive you of your hard earned cash for little to no return.

    Read the article

  • Building Effective Web Sites - Intro

    Here are several key components you should consider when building an effective web site. Mastering these elements will make your web site more visually appealing, user-friendly, and encourage repeat traffic.

    Read the article

  • Link Building - The Right Way

    The idea of link building is to generate quality inbound links pointed towards your websites. Nowadays search engines use this as a part of their algorithm with the help of which they can determine the significance of their websites.

    Read the article

  • Building Effective Web Sites - Intro

    Here are several key components you should consider when building an effective web site. Mastering these elements will make your web site more visually appealing, user-friendly, and encourage repeat traffic.

    Read the article

  • Building applications with WPF, MVVM and Prism(aka CAG)

    - by skjagini
    In this article I am going to walk through an application using WPF and Prism (aka composite application guidance, CAG) which simulates engaging a taxi (cab).  The rules are simple, the app would have3 screens A login screen to authenticate the user An information screen. A screen to engage the cab and roam around and calculating the total fare Metered Rate of Fare The meter is required to be engaged when a cab is occupied by anyone $3.00 upon entry $0.35 for each additional unit The unit fare is: one-fifth of a mile, when the cab is traveling at 6 miles an hour or more; or 60 seconds when not in motion or traveling at less than 12 miles per hour. Night surcharge of $.50 after 8:00 PM & before 6:00 AM Peak hour Weekday Surcharge of $1.00 Monday - Friday after 4:00 PM & before 8:00 PM New York State Tax Surcharge of $.50 per ride. Example: Friday (2010-10-08) 5:30pm Start at Lexington Ave & E 57th St End at Irving Pl & E 15th St Start = $3.00 Travels 2 miles at less than 6 mph for 15 minutes = $3.50 Travels at more than 12 mph for 5 minutes = $1.75 Peak hour Weekday Surcharge = $1.00 (ride started at 5:30 pm) New York State Tax Surcharge = $0.50 Before we dive into the app, I would like to give brief description about the framework.  If you want to jump on to the source code, scroll all the way to the end of the post. MVVM MVVM pattern is in no way related to the usage of PRISM in your application and should be considered if you are using WPF irrespective of PRISM or not. Lets say you are not familiar with MVVM, your typical UI would involve adding some UI controls like text boxes, a button, double clicking on the button,  generating event handler, calling a method from business layer and updating the user interface, it works most of the time for developing small scale applications. The problem with this approach is that there is some amount of code specific to business logic wrapped in UI specific code which is hard to unit test it, mock it and MVVM helps to solve the exact problem. MVVM stands for Model(M) – View(V) – ViewModel(VM),  based on the interactions with in the three parties it should be called VVMM,  MVVM sounds more like MVC (Model-View-Controller) so the name. Why it should be called VVMM: View – View Model - Model WPF allows to create user interfaces using XAML and MVVM takes it to the next level by allowing complete separation of user interface and business logic. In WPF each view will have a property, DataContext when set to an instance of a class (which happens to be your view model) provides the data the view is interested in, i.e., view interacts with view model and at the same time view model interacts with view through DataContext. Sujith, if view and view model are interacting directly with each other how does MVVM is helping me separation of concerns? Well, the catch is DataContext is of type Object, since it is of type object view doesn’t know exact type of view model allowing views and views models to be loosely coupled. View models aggregate data from models (data access layer, services, etc) and make it available for views through properties, methods etc, i.e., View Models interact with Models. PRISM Prism is provided by Microsoft Patterns and Practices team and it can be downloaded from codeplex for source code,  samples and documentation on msdn.  The name composite implies, to compose user interface from different modules (views) without direct dependencies on each other, again allowing  loosely coupled development. Well Sujith, I can already do that with user controls, why shall I learn another framework?  That’s correct, you can decouple using user controls, but you still have to manage some amount of coupling, like how to do you communicate between the controls, how do you subscribe/unsubscribe, loading/unloading views dynamically. Prism is not a replacement for user controls, provides the following features which greatly help in designing the composite applications. Dependency Injection (DI)/ Inversion of Control (IoC) Modules Regions Event Aggregator  Commands Simply put, MVVM helps building a single view and Prism helps building an application using the views There are other open source alternatives to Prism, like MVVMLight, Cinch, take a look at them as well. Lets dig into the source code.  1. Solution The solution is made of the following projects Framework: Holds the common functionality in building applications using WPF and Prism TaxiClient: Start up project, boot strapping and app styling TaxiCommon: Helps with the business logic TaxiModules: Holds the meat of the application with views and view models TaxiTests: To test the application 2. DI / IoC Dependency Injection (DI) as the name implies refers to injecting dependencies and Inversion of Control (IoC) means the calling code has no direct control on the dependencies, opposite of normal way of programming where dependencies are passed by caller, i.e inversion; aside from some differences in terminology the concept is same in both the cases. The idea behind DI/IoC pattern is to reduce the amount of direct coupling between different components of the application, the higher the dependency the more tightly coupled the application resulting in code which is hard to modify, unit test and mock.  Initializing Dependency Injection through BootStrapper TaxiClient is the starting project of the solution and App (App.xaml)  is the starting class that gets called when you run the application. From the App’s OnStartup method we will invoke BootStrapper.   namespace TaxiClient { /// <summary> /// Interaction logic for App.xaml /// </summary> public partial class App : Application { protected override void OnStartup(StartupEventArgs e) { base.OnStartup(e);   (new BootStrapper()).Run(); } } } BootStrapper is your contact point for initializing the application including dependency injection, creating Shell and other frameworks. We are going to use Unity for DI and there are lot of open source DI frameworks like Spring.Net, StructureMap etc with different feature set  and you can choose a framework based on your preferences. Note that Prism comes with in built support for Unity, for example we are deriving from UnityBootStrapper in our case and for any other DI framework you have to extend the Prism appropriately   namespace TaxiClient { public class BootStrapper: UnityBootstrapper { protected override IModuleCatalog CreateModuleCatalog() { return new ConfigurationModuleCatalog(); } protected override DependencyObject CreateShell() { Framework.FrameworkBootStrapper.Run(Container, Application.Current.Dispatcher);   Shell shell = new Shell(); shell.ResizeMode = ResizeMode.NoResize; shell.Show();   return shell; } } } Lets take a look into  FrameworkBootStrapper to check out how to register with unity container. namespace Framework { public class FrameworkBootStrapper { public static void Run(IUnityContainer container, Dispatcher dispatcher) { UIDispatcher uiDispatcher = new UIDispatcher(dispatcher); container.RegisterInstance<IDispatcherService>(uiDispatcher);   container.RegisterType<IInjectSingleViewService, InjectSingleViewService>( new ContainerControlledLifetimeManager());   . . . } } } In the above code we are registering two components with unity container. You shall observe that we are following two different approaches, RegisterInstance and RegisterType.  With RegisterInstance we are registering an existing instance and the same instance will be returned for every request made for IDispatcherService   and with RegisterType we are requesting unity container to create an instance for us when required, i.e., when I request for an instance for IInjectSingleViewService, unity will create/return an instance of InjectSingleViewService class and with RegisterType we can configure the life time of the instance being created. With ContaienrControllerLifetimeManager, the unity container caches the instance and reuses for any subsequent requests, without recreating a new instance. Lets take a look into FareViewModel.cs and it’s constructor. The constructor takes one parameter IEventAggregator and if you try to find all references in your solution for IEventAggregator, you will not find a single location where an instance of EventAggregator is passed directly to the constructor. The compiler still finds an instance and works fine because Prism is already configured when used with Unity container to return an instance of EventAggregator when requested for IEventAggregator and in this particular case it is called constructor injection. public class FareViewModel:ObservableBase, IDataErrorInfo { ... private IEventAggregator _eventAggregator;   public FareViewModel(IEventAggregator eventAggregator) { _eventAggregator = eventAggregator; InitializePropertyNames(); InitializeModel(); PropertyChanged += OnPropertyChanged; } ... 3. Shell Shells are very similar in operation to Master Pages in asp.net or MDI in Windows Forms. And shells contain regions which display the views, you can have as many regions as you wish in a given view. You can also nest regions. i.e, one region can load a view which in itself may contain other regions. We have to create a shell at the start of the application and are doing it by overriding CreateShell method from BootStrapper From the following Shell.xaml you shall notice that we have two content controls with Region names as ‘MenuRegion’ and ‘MainRegion’.  The idea here is that you can inject any user controls into the regions dynamically, i.e., a Menu User Control for MenuRegion and based on the user action you can load appropriate view into MainRegion.    <Window x:Class="TaxiClient.Shell" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" xmlns:Regions="clr-namespace:Microsoft.Practices.Prism.Regions;assembly=Microsoft.Practices.Prism" Title="Taxi" Height="370" Width="800"> <Grid Margin="2"> <ContentControl Regions:RegionManager.RegionName="MenuRegion" HorizontalAlignment="Stretch" VerticalAlignment="Stretch" HorizontalContentAlignment="Stretch" VerticalContentAlignment="Stretch" />   <ContentControl Grid.Row="1" Regions:RegionManager.RegionName="MainRegion" HorizontalAlignment="Stretch" VerticalAlignment="Stretch" HorizontalContentAlignment="Stretch" VerticalContentAlignment="Stretch" /> <!--<Border Grid.ColumnSpan="2" BorderThickness="2" CornerRadius="3" BorderBrush="LightBlue" />-->   </Grid> </Window> 4. Modules Prism provides the ability to build composite applications and modules play an important role in it. For example if you are building a Mortgage Loan Processor application with 3 components, i.e. customer’s credit history,  existing mortgages, new home/loan information; and consider that the customer’s credit history component involves gathering data about his/her address, background information, job details etc. The idea here using Prism modules is to separate the implementation of these 3 components into their own visual studio projects allowing to build components with no dependency on each other and independently. If we need to add another component to the application, the component can be developed by in house team or some other team in the organization by starting with a new Visual Studio project and adding to the solution at the run time with very little knowledge about the application. Prism modules are defined by implementing the IModule interface and each visual studio project to be considered as a module should implement the IModule interface.  From the BootStrapper.cs you shall observe that we are overriding the method by returning a ConfiguratingModuleCatalog which returns the modules that are registered for the application using the app.config file  and you can also add module using code. Lets take a look into configuration file.   <?xml version="1.0"?> <configuration> <configSections> <section name="modules" type="Microsoft.Practices.Prism.Modularity.ModulesConfigurationSection, Microsoft.Practices.Prism"/> </configSections> <modules> <module assemblyFile="TaxiModules.dll" moduleType="TaxiModules.ModuleInitializer, TaxiModules" moduleName="TaxiModules"/> </modules> </configuration> Here we are adding TaxiModules project to our solution and TaxiModules.ModuleInitializer implements IModule interface   5. Module Mapper With Prism modules you can dynamically add or remove modules from the regions, apart from that Prism also provides API to control adding/removing the views from a region within the same module. Taxi Information Screen: Engage the Taxi Screen: The sample application has two screens, ‘Taxi Information’ and ‘Engage the Taxi’ and they both reside in same module, TaxiModules. ‘Engage the Taxi’ is again made of two user controls, FareView on the left and TotalView on the right. We have created a Shell with two regions, MenuRegion and MainRegion with menu loaded into MenuRegion. We can create a wrapper user control called EngageTheTaxi made of FareView and TotalView and load either TaxiInfo or EngageTheTaxi into MainRegion based on the user action. Though it will work it tightly binds the user controls and for every combination of user controls, we need to create a dummy wrapper control to contain them. Instead we can apply the principles we learned so far from Shell/regions and introduce another template (LeftAndRightRegionView.xaml) made of two regions Region1 (left) and Region2 (right) and load  FareView and TotalView dynamically.  To help with loading of the views dynamically I have introduce an helper an interface, IInjectSingleViewService,  idea suggested by Mike Taulty, a must read blog for .Net developers. using System; using System.Collections.Generic; using System.ComponentModel;   namespace Framework.PresentationUtility.Navigation {   public interface IInjectSingleViewService : INotifyPropertyChanged { IEnumerable<CommandViewDefinition> Commands { get; } IEnumerable<ModuleViewDefinition> Modules { get; }   void RegisterViewForRegion(string commandName, string viewName, string regionName, Type viewType); void ClearViewFromRegion(string viewName, string regionName); void RegisterModule(string moduleName, IList<ModuleMapper> moduleMappers); } } The Interface declares three methods to work with views: RegisterViewForRegion: Registers a view with a particular region. You can register multiple views and their regions under one command.  When this particular command is invoked all the views registered under it will be loaded into their regions. ClearViewFromRegion: To unload a specific view from a region. RegisterModule: The idea is when a command is invoked you can load the UI with set of controls in their default position and based on the user interaction, you can load different contols in to different regions on the fly.  And it is supported ModuleViewDefinition and ModuleMappers as shown below. namespace Framework.PresentationUtility.Navigation { public class ModuleViewDefinition { public string ModuleName { get; set; } public IList<ModuleMapper> ModuleMappers; public ICommand Command { get; set; } }   public class ModuleMapper { public string ViewName { get; set; } public string RegionName { get; set; } public Type ViewType { get; set; } } } 6. Event Aggregator Prism event aggregator enables messaging between components as in Observable pattern, Notifier notifies the Observer which receives notification it is interested in. When it comes to Observable pattern, Observer has to unsubscribes for notifications when it no longer interested in notifications, which allows the Notifier to remove the Observer’s reference from it’s local cache. Though .Net has managed garbage collection it cannot remove inactive the instances referenced by an active instance resulting in memory leak, keeping the Observers in memory as long as Notifier stays in memory.  Developers have to be very careful to unsubscribe when necessary and it often gets overlooked, to overcome these problems Prism Event Aggregator uses weak references to cache the reference (Observer in this case)  and releases the reference (memory) once the instance goes out of scope. Using event aggregator is very simple, declare a generic type of CompositePresenationEvent by inheriting from it. using Microsoft.Practices.Prism.Events; using TaxiCommon.BAO;   namespace TaxiCommon.CompositeEvents { public class TaxiOnMoveEvent:CompositePresentationEvent<TaxiOnMove> { } }   TaxiOnMove.cs includes the properties which we want to exchange between the parties, FareView and TotalView. using System;   namespace TaxiCommon.BAO { public class TaxiOnMove { public TimeSpan MinutesAtTweleveMPH { get; set; } public double MilesAtSixMPH { get; set; } } }   Lets take a look into FareViewodel (Notifier) and how it raises the event.  Here we are raising the event by getting the event through GetEvent<..>() and publishing it with the payload private void OnAddMinutes(object obj) { TaxiOnMove payload = new TaxiOnMove(); if(MilesAtSixMPH != null) payload.MilesAtSixMPH = MilesAtSixMPH.Value; if(MinutesAtTweleveMPH != null) payload.MinutesAtTweleveMPH = new TimeSpan(0,0,MinutesAtTweleveMPH.Value,0);   _eventAggregator.GetEvent<TaxiOnMoveEvent>().Publish(payload); ResetMinutesAndMiles(); } And TotalViewModel(Observer) subscribes to notifications by getting the event through GetEvent<..>() namespace TaxiModules.ViewModels { public class TotalViewModel:ObservableBase { .... private IEventAggregator _eventAggregator;   public TotalViewModel(IEventAggregator eventAggregator) { _eventAggregator = eventAggregator; ... }   private void SubscribeToEvents() { _eventAggregator.GetEvent<TaxiStartedEvent>() .Subscribe(OnTaxiStarted, ThreadOption.UIThread,false,(filter) => true); _eventAggregator.GetEvent<TaxiOnMoveEvent>() .Subscribe(OnTaxiMove, ThreadOption.UIThread, false, (filter) => true); _eventAggregator.GetEvent<TaxiResetEvent>() .Subscribe(OnTaxiReset, ThreadOption.UIThread, false, (filter) => true); }   ... private void OnTaxiMove(TaxiOnMove taxiOnMove) { OnMoveFare fare = new OnMoveFare(taxiOnMove); Fares.Add(fare); SetTotalFare(new []{fare}); }   .... 7. MVVM through example In this section we are going to look into MVVM implementation through example.  I have all the modules declared in a single project, TaxiModules, again it is not necessary to have them into one project. Once the user logs into the application, will be greeted with the ‘Engage the Taxi’ screen which is made of two user controls, FareView.xaml and TotalView.Xaml. As you can see from the solution explorer, each of them have their own code behind files and  ViewModel classes, FareViewMode.cs, TotalViewModel.cs Lets take a look in to the FareView and how it interacts with FareViewModel using MVVM implementation. FareView.xaml acts as a view and FareViewMode.cs is it’s view model. The FareView code behind class   namespace TaxiModules.Views { /// <summary> /// Interaction logic for FareView.xaml /// </summary> public partial class FareView : UserControl { public FareView(FareViewModel viewModel) { InitializeComponent(); this.Loaded += (s, e) => { this.DataContext = viewModel; }; } } } The FareView is bound to FareViewModel through the data context  and you shall observe that DataContext is of type Object, i.e. the FareView doesn’t really know the type of ViewModel (FareViewModel). This helps separation of View and ViewModel as View and ViewModel are independent of each other, you can bind FareView to FareViewModel2 as well and the application compiles just fine. Lets take a look into FareView xaml file  <UserControl x:Class="TaxiModules.Views.FareView" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" xmlns:Toolkit="clr-namespace:Microsoft.Windows.Controls;assembly=WPFToolkit" xmlns:Commands="clr-namespace:Microsoft.Practices.Prism.Commands;assembly=Microsoft.Practices.Prism"> <Grid Margin="10" > ....   <Border Style="{DynamicResource innerBorder}" Grid.Row="0" Grid.Column="0" Grid.RowSpan="11" Grid.ColumnSpan="2" Panel.ZIndex="1"/>   <Label Grid.Row="0" Content="Engage the Taxi" Style="{DynamicResource innerHeader}"/> <Label Grid.Row="1" Content="Select the State"/> <ComboBox Grid.Row="1" Grid.Column="1" ItemsSource="{Binding States}" Height="auto"> <ComboBox.ItemTemplate> <DataTemplate> <TextBlock Text="{Binding Name}"/> </DataTemplate> </ComboBox.ItemTemplate> <ComboBox.SelectedItem> <Binding Path="SelectedState" Mode="TwoWay"/> </ComboBox.SelectedItem> </ComboBox> <Label Grid.Row="2" Content="Select the Date of Entry"/> <Toolkit:DatePicker Grid.Row="2" Grid.Column="1" SelectedDate="{Binding DateOfEntry, ValidatesOnDataErrors=true}" /> <Label Grid.Row="3" Content="Enter time 24hr format"/> <TextBox Grid.Row="3" Grid.Column="1" Text="{Binding TimeOfEntry, TargetNullValue=''}"/> <Button Grid.Row="4" Grid.Column="1" Content="Start the Meter" Commands:Click.Command="{Binding StartMeterCommand}" />   <Label Grid.Row="5" Content="Run the Taxi" Style="{DynamicResource innerHeader}"/> <Label Grid.Row="6" Content="Number of Miles &lt;@6mph"/> <TextBox Grid.Row="6" Grid.Column="1" Text="{Binding MilesAtSixMPH, TargetNullValue='', ValidatesOnDataErrors=true}"/> <Label Grid.Row="7" Content="Number of Minutes @12mph"/> <TextBox Grid.Row="7" Grid.Column="1" Text="{Binding MinutesAtTweleveMPH, TargetNullValue=''}"/> <Button Grid.Row="8" Grid.Column="1" Content="Add Minutes and Miles " Commands:Click.Command="{Binding AddMinutesCommand}"/> <Label Grid.Row="9" Content="Other Operations" Style="{DynamicResource innerHeader}"/> <Button Grid.Row="10" Grid.Column="1" Content="Reset the Meter" Commands:Click.Command="{Binding ResetCommand}"/>   </Grid> </UserControl> The highlighted code from the above code shows data binding, for example ComboBox which displays list of states has it’s ItemsSource bound to States property, with DataTemplate bound to Name and SelectedItem  to SelectedState. You might be wondering what are all these properties and how it is able to bind to them.  The answer lies in data context, i.e., when you bound a control, WPF looks for data context on the root object (Grid in this case) and if it can’t find data context it will look into root’s root, i.e. FareView UserControl and it is bound to FareViewModel.  Each of those properties have be declared on the ViewModel for the View to bind correctly. To put simply, View is bound to ViewModel through data context of type object and every control that is bound on the View actually binds to the public property on the ViewModel. Lets look into the ViewModel code (the following code is not an exact copy of FareViewMode.cs, pasted relevant code for this section)   namespace TaxiModules.ViewModels { public class FareViewModel:ObservableBase, IDataErrorInfo { public List<USState> States { get { return USStates.StateList; } }   public USState SelectedState { get { return _selectedState; } set { _selectedState = value; RaisePropertyChanged(_selectedStatePropertyName); } }   public DateTime? DateOfEntry { get { return _dateOfEntry; } set { _dateOfEntry = value; RaisePropertyChanged(_dateOfEntryPropertyName); } }   public TimeSpan? TimeOfEntry { get { return _timeOfEntry; } set { _timeOfEntry = value; RaisePropertyChanged(_timeOfEntryPropertyName); } }   public double? MilesAtSixMPH { get { return _milesAtSixMPH; } set { _milesAtSixMPH = value; RaisePropertyChanged(_distanceAtSixMPHPropertyName); } }   public int? MinutesAtTweleveMPH { get { return _minutesAtTweleveMPH; } set { _minutesAtTweleveMPH = value; RaisePropertyChanged(_minutesAtTweleveMPHPropertyName); } }   public ICommand StartMeterCommand { get { if(_startMeterCommand == null) { _startMeterCommand = new DelegateCommand<object>(OnStartMeter, CanStartMeter); } return _startMeterCommand; } }   public ICommand AddMinutesCommand { get { if(_addMinutesCommand == null) { _addMinutesCommand = new DelegateCommand<object>(OnAddMinutes, CanAddMinutes); } return _addMinutesCommand; } }   public ICommand ResetCommand { get { if(_resetCommand == null) { _resetCommand = new DelegateCommand<object>(OnResetCommand); } return _resetCommand; } }   } private void OnStartMeter(object obj) { _eventAggregator.GetEvent<TaxiStartedEvent>().Publish( new TaxiStarted() { EngagedOn = DateOfEntry.Value.Date + TimeOfEntry.Value, EngagedState = SelectedState.Value });   _isMeterStarted = true; OnPropertyChanged(this,null); } And views communicate user actions like button clicks, tree view item selections, etc using commands. When user clicks on ‘Start the Meter’ button it invokes the method StartMeterCommand, which calls the method OnStartMeter which publishes the event to TotalViewModel using event aggregator  and TaxiStartedEvent. namespace TaxiModules.ViewModels { public class TotalViewModel:ObservableBase { ... private IEventAggregator _eventAggregator;   public TotalViewModel(IEventAggregator eventAggregator) { _eventAggregator = eventAggregator;   InitializePropertyNames(); InitializeModel(); SubscribeToEvents(); }   public decimal? TotalFare { get { return _totalFare; } set { _totalFare = value; RaisePropertyChanged(_totalFarePropertyName); } } .... private void SubscribeToEvents() { _eventAggregator.GetEvent<TaxiStartedEvent>().Subscribe(OnTaxiStarted, ThreadOption.UIThread,false,(filter) => true); _eventAggregator.GetEvent<TaxiOnMoveEvent>().Subscribe(OnTaxiMove, ThreadOption.UIThread, false, (filter) => true); _eventAggregator.GetEvent<TaxiResetEvent>().Subscribe(OnTaxiReset, ThreadOption.UIThread, false, (filter) => true); }   private void OnTaxiStarted(TaxiStarted taxiStarted) { Fares.Add(new EntryFare()); Fares.Add(new StateTaxFare(taxiStarted)); Fares.Add(new NightSurchargeFare(taxiStarted)); Fares.Add(new PeakHourWeekdayFare(taxiStarted));   SetTotalFare(Fares); }   private void SetTotalFare(IEnumerable<IFare> fares) { TotalFare = (_totalFare ?? 0) + TaxiFareHelper.GetTotalFare(fares); } ....   } }   TotalViewModel subscribes to events, TaxiStartedEvent and rest. When TaxiStartedEvent gets invoked it calls the OnTaxiStarted method which sets the total fare which includes entry fee, state tax, nightly surcharge, peak hour weekday fare.   Note that TotalViewModel derives from ObservableBase which implements the method RaisePropertyChanged which we are invoking in Set of TotalFare property, i.e, once we update the TotalFare property it raises an the event that  allows the TotalFare text box to fetch the new value through the data context. ViewModel is communicating with View through data context and it has no knowledge about View, helping in loose coupling of ViewModel and View.   I have attached the source code (.Net 4.0, Prism 4.0, VS 2010) , download and play with it and don’t forget to leave your comments.  

    Read the article

  • Building Awesome WM

    - by Dragan Chupacabrovic
    Hello, I am following these steps in order to build Awesome window manager on 10.04 I am building 3.4 while the tutorial is for 3.1 I installed all of the specified dependencies including cairo. After running cd awesome-3.4 && make I get the following missing dependencies error: Running cmake… -- cat - /bin/cat -- ln - /bin/ln -- grep - /bin/grep -- git - /usr/bin/git -- hostname - /bin/hostname -- gperf - /usr/bin/gperf -- asciidoc - /usr/bin/asciidoc -- xmlto - /usr/bin/xmlto -- gzip - /bin/gzip -- lua - /usr/bin/lua -- luadoc - /usr/bin/luadoc -- convert - /usr/bin/convert -- checking for modules 'glib-2.0;cairo;x11;pango=1.19.3;pangocairo=1.19.3;xcb-randr;xcb-xtest;xcb-xinerama;xcb-shape;xcb-event=0.3.6;xcb-aux=0.3.0;xcb-atom=0.3.0;xcb-keysyms=0.3.4;xcb-icccm=0.3.6;xcb-image=0.3.0;xcb-property=0.3.0;cairo-xcb;libstartup-notification-1.0=0.10;xproto=7.0.15;imlib2;libxdg-basedir=1.0.0' -- package 'xcb-xtest' not found -- package 'xcb-property=0.3.0' not found -- package 'libstartup-notification-1.0=0.10' not found -- package 'libxdg-basedir=1.0.0' not found CMake Error at /usr/share/cmake-2.8/Modules/FindPkgConfig.cmake:259 (message): A required package was not found Call Stack (most recent call first): /usr/share/cmake-2.8/Modules/FindPkgConfig.cmake:311 (_pkg_check_modules_internal) awesomeConfig.cmake:133 (pkg_check_modules) CMakeLists.txt:15 (include) CMake Error at awesomeConfig.cmake:157 (message): Call Stack (most recent call first): CMakeLists.txt:15 (include) -- Configuring incomplete, errors occurred! make: * [cmake] Error 1 I ran sudo apt-get install libxcb-xtest0 libxcb-property1 libxdg-basedir1 libstartup-notification0 but the problem is still there. It is probably because apt-get uses different names for these libraries. Please advise EDIT following enzotib's suggestion, I ran: sudo apt-get install libxcb-xtest0-dev libxcb-property1-dev libxdg-basedir-dev libstartup-notification0-dev and now it looks like I'm missing a library: awesome-3.4$ make Running cmake… -- cat - /bin/cat -- ln - /bin/ln -- grep - /bin/grep -- git - /usr/bin/git -- hostname - /bin/hostname -- gperf - /usr/bin/gperf -- asciidoc - /usr/bin/asciidoc -- xmlto - /usr/bin/xmlto -- gzip - /bin/gzip -- lua - /usr/bin/lua -- luadoc - /usr/bin/luadoc -- convert - /usr/bin/convert -- Configuring lib/naughty.lua -- Configuring lib/awful/tooltip.lua -- Configuring lib/awful/init.lua -- Configuring lib/awful/titlebar.lua -- Configuring lib/awful/key.lua -- Configuring lib/awful/mouse/init.lua -- Configuring lib/awful/mouse/finder.lua -- Configuring lib/awful/autofocus.lua -- Configuring lib/awful/screen.lua -- Configuring lib/awful/rules.lua -- Configuring lib/awful/widget/init.lua -- Configuring lib/awful/widget/taglist.lua -- Configuring lib/awful/widget/graph.lua -- Configuring lib/awful/widget/tasklist.lua -- Configuring lib/awful/widget/common.lua -- Configuring lib/awful/widget/prompt.lua -- Configuring lib/awful/widget/launcher.lua -- Configuring lib/awful/widget/button.lua -- Configuring lib/awful/widget/layoutbox.lua -- Configuring lib/awful/widget/layout/init.lua -- Configuring lib/awful/widget/layout/vertical.lua -- Configuring lib/awful/widget/layout/horizontal.lua -- Configuring lib/awful/widget/layout/default.lua -- Configuring lib/awful/widget/progressbar.lua -- Configuring lib/awful/widget/textclock.lua -- Configuring lib/awful/dbus.lua -- Configuring lib/awful/remote.lua -- Configuring lib/awful/client.lua -- Configuring lib/awful/prompt.lua -- Configuring lib/awful/completion.lua -- Configuring lib/awful/tag.lua -- Configuring lib/awful/util.lua -- Configuring lib/awful/button.lua -- Configuring lib/awful/menu.lua -- Configuring lib/awful/hooks.lua -- Configuring lib/awful/wibox.lua -- Configuring lib/awful/layout/init.lua -- Configuring lib/awful/layout/suit/init.lua -- Configuring lib/awful/layout/suit/floating.lua -- Configuring lib/awful/layout/suit/fair.lua -- Configuring lib/awful/layout/suit/spiral.lua -- Configuring lib/awful/layout/suit/magnifier.lua -- Configuring lib/awful/layout/suit/tile.lua -- Configuring lib/awful/layout/suit/max.lua -- Configuring lib/awful/placement.lua -- Configuring lib/awful/startup_notification.lua -- Configuring lib/beautiful.lua -- Configuring themes/zenburn//theme.lua -- Configuring themes/default//theme.lua -- Configuring themes/sky//theme.lua -- Configuring config.h -- Configuring awesomerc.lua -- Configuring awesome-version-internal.h -- Configuring awesome.doxygen -- Configuring done -- Generating done -- Build files have been written to: /home/druden/util/awesome-3.4/.build-vedroid-i486-linux-gnu-4.4.3 Running make Makefile… Building… [ 4%] Built target generated_sources [ 5%] Building C object CMakeFiles/awesome.dir/awesome.c.o In file included from /home/druden/util/awesome-3.4/spawn.h:25, from /home/druden/util/awesome-3.4/awesome.c:33: /home/druden/util/awesome-3.4/globalconf.h:57: error: expected specifier-qualifier-list before ‘xcb_event_handlers_t’ In file included from /home/druden/util/awesome-3.4/awesome.c:34: /home/druden/util/awesome-3.4/client.h: In function ‘client_stack’: /home/druden/util/awesome-3.4/client.h:212: error: ‘awesome_t’ has no member named ‘client_need_stack_refresh’ /home/druden/util/awesome-3.4/client.h: In function ‘client_raise’: /home/druden/util/awesome-3.4/client.h:227: error: ‘awesome_t’ has no member named ‘stack’ In file included from /home/druden/util/awesome-3.4/awesome.c:42: /home/druden/util/awesome-3.4/titlebar.h: In function ‘titlebar_update_geometry’: /home/druden/util/awesome-3.4/titlebar.h:150: error: ‘awesome_t’ has no member named ‘L’ /home/druden/util/awesome-3.4/titlebar.h:151: error: ‘awesome_t’ has no member named ‘L’ /home/druden/util/awesome-3.4/titlebar.h:152: error: ‘awesome_t’ has no member named ‘L’ In file included from /home/druden/util/awesome-3.4/awesome.c:47: /home/druden/util/awesome-3.4/common/xutil.h: In function ‘xutil_get_text_property_from_reply’: /home/druden/util/awesome-3.4/common/xutil.h:39: warning: ‘STRING’ is deprecated (declared at /usr/local/include/xcb/xcb_atom.h:83) /home/druden/util/awesome-3.4/common/xutil.h: At top level: /home/druden/util/awesome-3.4/common/xutil.h:60: error: expected ‘)’ before ‘*’ token /home/druden/util/awesome-3.4/awesome.c: In function ‘awesome_atexit’: /home/druden/util/awesome-3.4/awesome.c:65: error: ‘awesome_t’ has no member named ‘hooks’ /home/druden/util/awesome-3.4/awesome.c:66: error: ‘awesome_t’ has no member named ‘L’ /home/druden/util/awesome-3.4/awesome.c:66: error: ‘awesome_t’ has no member named ‘hooks’ /home/druden/util/awesome-3.4/awesome.c:68: error: ‘awesome_t’ has no member named ‘L’ /home/druden/util/awesome-3.4/awesome.c:73: error: ‘awesome_t’ has no member named ‘embedded’ /home/druden/util/awesome-3.4/awesome.c:76: error: ‘awesome_t’ has no member named ‘embedded’ /home/druden/util/awesome-3.4/awesome.c:77: error: ‘awesome_t’ has no member named ‘embedded’ /home/druden/util/awesome-3.4/awesome.c:89: error: ‘awesome_t’ has no member named ‘clients’ /home/druden/util/awesome-3.4/awesome.c:89: error: ‘awesome_t’ has no member named ‘clients’ /home/druden/util/awesome-3.4/awesome.c:89: error: ‘awesome_t’ has no member named ‘clients’ /home/druden/util/awesome-3.4/awesome.c:89: warning: type defaults to ‘int’ in declaration of ‘c’ /home/druden/util/awesome-3.4/awesome.c:89: error: ‘awesome_t’ has no member named ‘clients’ /home/druden/util/awesome-3.4/awesome.c:89: error: ‘awesome_t’ has no member named ‘clients’ /home/druden/util/awesome-3.4/awesome.c:89: error: ‘awesome_t’ has no member named ‘clients’ /home/druden/util/awesome-3.4/awesome.c:91: error: invalid type argument of ‘unary *’ (have ‘int’) /home/druden/util/awesome-3.4/awesome.c:92: error: invalid type argument of ‘unary *’ (have ‘int’) /home/druden/util/awesome-3.4/awesome.c:96: error: ‘awesome_t’ has no member named ‘L’ /home/druden/util/awesome-3.4/awesome.c: In function ‘a_xcb_check_cb’: /home/druden/util/awesome-3.4/awesome.c:223: warning: implicit declaration of function ‘xcb_event_handle’ /home/druden/util/awesome-3.4/awesome.c:223: error: ‘awesome_t’ has no member named ‘evenths’ /home/druden/util/awesome-3.4/awesome.c:230: error: ‘awesome_t’ has no member named ‘evenths’ /home/druden/util/awesome-3.4/awesome.c: In function ‘awesome_restart’: /home/druden/util/awesome-3.4/awesome.c:277: error: ‘awesome_t’ has no member named ‘argv’ /home/druden/util/awesome-3.4/awesome.c: In function ‘xerror’: /home/druden/util/awesome-3.4/awesome.c:305: error: ‘XCB_EVENT_ERROR_BAD_WINDOW’ undeclared (first use in this function) /home/druden/util/awesome-3.4/awesome.c:305: error: (Each undeclared identifier is reported only once /home/druden/util/awesome-3.4/awesome.c:305: error: for each function it appears in.) /home/druden/util/awesome-3.4/awesome.c:306: error: ‘XCB_EVENT_ERROR_BAD_MATCH’ undeclared (first use in this function) /home/druden/util/awesome-3.4/awesome.c:308: error: ‘XCB_EVENT_ERROR_BAD_VALUE’ undeclared (first use in this function) /home/druden/util/awesome-3.4/awesome.c: In function ‘main’: /home/druden/util/awesome-3.4/awesome.c:369: error: ‘awesome_t’ has no member named ‘keygrabber’ /home/druden/util/awesome-3.4/awesome.c:370: error: ‘awesome_t’ has no member named ‘mousegrabber’ /home/druden/util/awesome-3.4/awesome.c:376: error: ‘awesome_t’ has no member named ‘argv’ /home/druden/util/awesome-3.4/awesome.c:377: error: ‘awesome_t’ has no member named ‘argv’ /home/druden/util/awesome-3.4/awesome.c:381: error: ‘awesome_t’ has no member named ‘argv’ /home/druden/util/awesome-3.4/awesome.c:382: error: ‘awesome_t’ has no member named ‘argv’ /home/druden/util/awesome-3.4/awesome.c:424: error: ‘awesome_t’ has no member named ‘loop’ /home/druden/util/awesome-3.4/awesome.c:425: error: ‘awesome_t’ has no member named ‘timer’ /home/druden/util/awesome-3.4/awesome.c:425: error: ‘awesome_t’ has no member named ‘timer’ /home/druden/util/awesome-3.4/awesome.c:425: error: ‘awesome_t’ has no member named ‘timer’ /home/druden/util/awesome-3.4/awesome.c:425: error: ‘awesome_t’ has no member named ‘timer’ /home/druden/util/awesome-3.4/awesome.c:425: error: ‘awesome_t’ has no member named ‘timer’ /home/druden/util/awesome-3.4/awesome.c:425: error: ‘awesome_t’ has no member named ‘timer’ /home/druden/util/awesome-3.4/awesome.c:431: error: ‘awesome_t’ has no member named ‘loop’ /home/druden/util/awesome-3.4/awesome.c:432: error: ‘awesome_t’ has no member named ‘loop’ /home/druden/util/awesome-3.4/awesome.c:433: error: ‘awesome_t’ has no member named ‘loop’ /home/druden/util/awesome-3.4/awesome.c:434: error: ‘awesome_t’ has no member named ‘loop’ /home/druden/util/awesome-3.4/awesome.c:435: error: ‘awesome_t’ has no member named ‘loop’ /home/druden/util/awesome-3.4/awesome.c:436: error: ‘awesome_t’ has no member named ‘loop’ /home/druden/util/awesome-3.4/awesome.c:443: error: ‘awesome_t’ has no member named ‘default_screen’ /home/druden/util/awesome-3.4/awesome.c:450: error: ‘awesome_t’ has no member named ‘have_xtest’ /home/druden/util/awesome-3.4/awesome.c:462: error: ‘awesome_t’ has no member named ‘loop’ /home/druden/util/awesome-3.4/awesome.c:464: error: ‘awesome_t’ has no member named ‘loop’ /home/druden/util/awesome-3.4/awesome.c:465: error: ‘awesome_t’ has no member named ‘loop’ /home/druden/util/awesome-3.4/awesome.c:467: error: ‘awesome_t’ has no member named ‘loop’ /home/druden/util/awesome-3.4/awesome.c:468: error: ‘awesome_t’ has no member named ‘loop’ /home/druden/util/awesome-3.4/awesome.c:471: warning: implicit declaration of function ‘xcb_event_handlers_init’ /home/druden/util/awesome-3.4/awesome.c:471: error: ‘awesome_t’ has no member named ‘evenths’ /home/druden/util/awesome-3.4/awesome.c:472: warning: implicit declaration of function ‘xutil_error_handler_catch_all_set’ /home/druden/util/awesome-3.4/awesome.c:472: error: ‘awesome_t’ has no member named ‘evenths’ /home/druden/util/awesome-3.4/awesome.c:490: warning: implicit declaration of function ‘xcb_event_poll_for_event_loop’ /home/druden/util/awesome-3.4/awesome.c:490: error: ‘awesome_t’ has no member named ‘evenths’ /home/druden/util/awesome-3.4/awesome.c:493: error: ‘awesome_t’ has no member named ‘evenths’ /home/druden/util/awesome-3.4/awesome.c:496: error: ‘awesome_t’ has no member named ‘keysyms’ /home/druden/util/awesome-3.4/awesome.c:507: error: ‘awesome_t’ has no member named ‘colors’ /home/druden/util/awesome-3.4/awesome.c:510: error: ‘awesome_t’ has no member named ‘colors’ /home/druden/util/awesome-3.4/awesome.c:513: error: ‘awesome_t’ has no member named ‘font’ /home/druden/util/awesome-3.4/awesome.c:519: error: ‘awesome_t’ has no member named ‘keysyms’ /home/druden/util/awesome-3.4/awesome.c:519: error: ‘awesome_t’ has no member named ‘numlockmask’ /home/druden/util/awesome-3.4/awesome.c:520: error: ‘awesome_t’ has no member named ‘shiftlockmask’ /home/druden/util/awesome-3.4/awesome.c:520: error: ‘awesome_t’ has no member named ‘capslockmask’ /home/druden/util/awesome-3.4/awesome.c:521: error: ‘awesome_t’ has no member named ‘modeswitchmask’ /home/druden/util/awesome-3.4/awesome.c:563: error: ‘awesome_t’ has no member named ‘evenths’ /home/druden/util/awesome-3.4/awesome.c:572: error: ‘awesome_t’ has no member named ‘loop’ /home/druden/util/awesome-3.4/awesome.c:575: error: ‘awesome_t’ has no member named ‘loop’ /home/druden/util/awesome-3.4/awesome.c:576: error: ‘awesome_t’ has no member named ‘loop’ /home/druden/util/awesome-3.4/awesome.c:577: error: ‘awesome_t’ has no member named ‘loop’ /home/druden/util/awesome-3.4/awesome.c:578: error: ‘awesome_t’ has no member named ‘loop’ /home/druden/util/awesome-3.4/awesome.c:579: error: ‘awesome_t’ has no member named ‘loop’ /home/druden/util/awesome-3.4/awesome.c:580: error: ‘awesome_t’ has no member named ‘loop’ make[3]: * [CMakeFiles/awesome.dir/awesome.c.o] Error 1 make[2]: [CMakeFiles/awesome.dir/all] Error 2 make[1]: [all] Error 2 make: * [cmake-build] Error 2

    Read the article

  • Building a Windows Phone 7 Twitter Application using Silverlight

    - by ScottGu
    On Monday I had the opportunity to present the MIX 2010 Day 1 Keynote in Las Vegas (you can watch a video of it here).  In the keynote I announced the release of the Silverlight 4 Release Candidate (we’ll ship the final release of it next month) and the VS 2010 RC tools for Silverlight 4.  I also had the chance to talk for the first time about how Silverlight and XNA can now be used to build Windows Phone 7 applications. During my talk I did two quick Windows Phone 7 coding demos using Silverlight – a quick “Hello World” application and a “Twitter” data-snacking application.  Both applications were easy to build and only took a few minutes to create on stage.  Below are the steps you can follow yourself to build them on your own machines as well. [Note: In addition to blogging, I am also now using Twitter for quick updates and to share links. Follow me at: twitter.com/scottgu] Building a “Hello World” Windows Phone 7 Application First make sure you’ve installed the Windows Phone Developer Tools CTP – this includes the Visual Studio 2010 Express for Windows Phone development tool (which will be free forever and is the only thing you need to develop and build Windows Phone 7 applications) as well as an add-on to the VS 2010 RC that enables phone development within the full VS 2010 as well. After you’ve downloaded and installed the Windows Phone Developer Tools CTP, launch the Visual Studio 2010 Express for Windows Phone that it installs or launch the VS 2010 RC (if you have it already installed), and then choose “File”->”New Project.”  Here, you’ll find the usual list of project template types along with a new category: “Silverlight for Windows Phone”. The first CTP offers two application project templates. The first is the “Windows Phone Application” template - this is what we’ll use for this example. The second is the “Windows Phone List Application” template - which provides the basic layout for a master-details phone application: After creating a new project, you’ll get a view of the design surface and markup. Notice that the design surface shows the phone UI, letting you easily see how your application will look while you develop. For those familiar with Visual Studio, you’ll also find the familiar ToolBox, Solution Explorer and Properties pane. For our HelloWorld application, we’ll start out by adding a TextBox and a Button from the Toolbox. Notice that you get the same design experience as you do for Silverlight on the web or desktop. You can easily resize, position and align your controls on the design surface. Changing properties is easy with the Properties pane. We’ll change the name of the TextBox that we added to username and change the page title text to “Hello world.” We’ll then write some code by double-clicking on the button and create an event handler in the code-behind file (MainPage.xaml.cs). We’ll start out by changing the title text of the application. The project template included this title as a TextBlock with the name textBlockListTitle (note that the current name incorrectly includes the word “list”; that will be fixed for the final release.)  As we write code against it we get intellisense showing the members available.  Below we’ll set the Text property of the title TextBlock to “Hello “ + the Text property of the TextBox username: We now have all the code necessary for a Hello World application.  We have two choices when it comes to deploying and running the application. We can either deploy to an actual device itself or use the built-in phone emulator: Because the phone emulator is actually the phone operating system running in a virtual machine, we’ll get the same experience developing in the emulator as on the device. For this sample, we’ll just press F5 to start the application with debugging using the emulator.  Once the phone operating system loads, the emulator will run the new “Hello world” application exactly as it would on the device: Notice that we can change several settings of the emulator experience with the emulator toolbar – which is a floating toolbar on the top right.  This includes the ability to re-size/zoom the emulator and two rotate buttons.  Zoom lets us zoom into even the smallest detail of the application: The orientation buttons allow us easily see what the application looks like in landscape mode (orientation change support is just built into the default template): Note that the emulator can be reused across F5 debug sessions - that means that we don’t have to start the emulator for every deployment. We’ve added a dialog that will help you from accidentally shutting down the emulator if you want to reuse it.  Launching an application on an already running emulator should only take ~3 seconds to deploy and run. Within our Hello World application we’ll click the “username” textbox to give it focus.  This will cause the software input panel (SIP) to open up automatically.  We can either type a message or – since we are using the emulator – just type in text.  Note that the emulator works with Windows 7 multi-touch so, if you have a touchscreen, you can see how interaction will feel on a device just by pressing the screen. We’ll enter “MIX 10” in the textbox and then click the button – this will cause the title to update to be “Hello MIX 10”: We provide the same Visual Studio experience when developing for the phone as other .NET applications. This means that we can set a breakpoint within the button event handler, press the button again and have it break within the debugger: Building a “Twitter” Windows Phone 7 Application using Silverlight Rather than just stop with “Hello World” let’s keep going and evolve it to be a basic Twitter client application. We’ll return to the design surface and add a ListBox, using the snaplines within the designer to fit it to the device screen and make the best use of phone screen real estate.  We’ll also rename the Button “Lookup”: We’ll then return to the Button event handler in Main.xaml.cs, and remove the original “Hello World” line of code and take advantage of the WebClient networking class to asynchronously download a Twitter feed. This takes three lines of code in total: (1) declaring and creating the WebClient, (2) attaching an event handler and then (3) calling the asynchronous DownloadStringAsync method. In the DownloadStringAsync call, we’ll pass a Twitter Uri plus a query string which pulls the text from the “username” TextBox. This feed will pull down the respective user’s most frequent posts in an XML format. When the call completes, the DownloadStringCompleted event is fired and our generated event handler twitter_DownloadStringCompleted will be called: The result returned from the Twitter call will come back in an XML based format.  To parse this we’ll use LINQ to XML. LINQ to XML lets us create simple queries for accessing data in an xml feed. To use this library, we’ll first need to add a reference to the assembly (right click on the References folder in the solution explorer and choose “Add Reference): We’ll then add a “using System.Xml.Linq” namespace reference at the top of the code-behind file at the top of Main.xaml.cs file: We’ll then add a simple helper class called TwitterItem to our project. TwitterItem has three string members – UserName, Message and ImageSource: We’ll then implement the twitter_DownloadStringCompleted event handler and use LINQ to XML to parse the returned XML string from Twitter.  What the query is doing is pulling out the three key pieces of information for each Twitter post from the username we passed as the query string. These are the ImageSource for their profile image, the Message of their tweet and their UserName. For each Tweet in the XML, we are creating a new TwitterItem in the IEnumerable<XElement> returned by the Linq query.  We then assign the generated TwitterItem sequence to the ListBox’s ItemsSource property: We’ll then do one more step to complete the application. In the Main.xaml file, we’ll add an ItemTemplate to the ListBox. For the demo, I used a simple template that uses databinding to show the user’s profile image, their tweet and their username. <ListBox Height="521" HorizonalAlignment="Left" Margin="0,131,0,0" Name="listBox1" VerticalAlignment="Top" Width="476"> <ListBox.ItemTemplate> <DataTemplate> <StackPanel Orientation="Horizontal" Height="132"> <Image Source="{Binding ImageSource}" Height="73" Width="73" VerticalAlignment="Top" Margin="0,10,8,0"/> <StackPanel Width="370"> <TextBlock Text="{Binding UserName}" Foreground="#FFC8AB14" FontSize="28" /> <TextBlock Text="{Binding Message}" TextWrapping="Wrap" FontSize="24" /> </StackPanel> </StackPanel> </DataTemplate> </ListBox.ItemTemplate> </ListBox> Now, pressing F5 again, we are able to reuse the emulator and re-run the application. Once the application has launched, we can type in a Twitter username and press the  Button to see the results. Try my Twitter user name (scottgu) and you’ll get back a result of TwitterItems in the Listbox: Try using the mouse (or if you have a touchscreen device your finger) to scroll the items in the Listbox – you should find that they move very fast within the emulator.  This is because the emulator is hardware accelerated – and so gives you the same fast performance that you get on the actual phone hardware. Summary Silverlight and the VS 2010 Tools for Windows Phone (and the corresponding Expression Blend Tools for Windows Phone) make building Windows Phone applications both really easy and fun.  At MIX this week a number of great partners (including Netflix, FourSquare, Seesmic, Shazaam, Major League Soccer, Graphic.ly, Associated Press, Jackson Fish and more) showed off some killer application prototypes they’ve built over the last few weeks.  You can watch my full day 1 keynote to see them in action. I think they start to show some of the promise and potential of using Silverlight with Windows Phone 7.  I’ll be doing more blog posts in the weeks and months ahead that cover that more. Hope this helps, Scott

    Read the article

facebook twitter digg google delicious technorati stumbleupon myspace wordpress linkedin gmail igoogle windows live tumblr viadeo yahoo buzz yahoo mail yahoo bookmarks favorites email print

< Previous Page | 6 7 8 9 10 11 12 13 14 15 16 17  | Next Page >